schleuder is semantically versioned

schleuder-gitlab-ticketing.gemspec

@@ -27,7 +27,7 @@ Gem::Specification.new do |s|
   }
   s.required_ruby_version = ">= 2.1.0"
   s.add_runtime_dependency 'gitlab', '~> 4.8'
-  s.add_runtime_dependency 'schleuder', '>= 3.3.0'
+  s.add_runtime_dependency 'schleuder', '~> 3.3'
   s.add_development_dependency 'rspec', '~> 3.5'
   s.post_install_message = "